When a load is suddenly reduced or suddenly increased in a switching regulator, the value of the output voltage usually exhibits an overshoot in value or an undershoot in value. The magnitude of the overshoot or undershoot depends on the size of various elements of the regulator. For example, the magnitude of the overshoot or undershoot may depend on the size of the inductor, the size of the output capacitor, the equivalent series resistance (ESR) of the output capacitor, the switching regulator control loop bandwidth and the switching frequency.
Using smaller sized inductors and larger sized capacitors generally minimizes the magnitude of the overshoot or undershoot. Design requirements, however, generally call for smaller sized capacitors to be used. There are also certain disadvantages in using smaller sized inductors. Reducing the size of an inductor creates larger ripple currents. Increasing the switching frequency reduces the efficiency of the switching regulator.
Therefore, there is a need in the art for a system and method that is capable of improving the performance of a switching regulator. There is a need in the art for a system and method that is capable of reducing the magnitude of a transient overshoot or a transient undershoot in a switching regulator without having to change the switching regulator control loop components, the control loop bandwidth or the switching frequency.